The Church of Scientology, stung by a five-part series in the Boston Herald that raised questions about its practices, has hired a private investigator to delve into the Herald reporter’s private life.

The Rev. Heber Jentzsch, president of the Church of Scientology International, confirmed that the church’s Los Angeles law firm hired the private investigative firm to look into the personal life of reporter Joseph Mallia, who wrote the series.

“This investigation will have to look at what’s riving this” coverage, said Jentzsch.

The investigator, Steve Long of Vision Investigative Services in Rohnert Park, Calif., contacted Mallia’s ex-wife in Berkeley, Calif., March 3.

Long told the woman he was looking for derogatory information, according to the former wife, whose name is being withheld for reasons of privacy.

“I’m looking for the ‘scorned wife’ story,” she said Long told her. She said she declined to provide information about her divorce, which took place more than 15 years ago.

The Church of Scientology is the only religious organization in the U.S. that uses private investigators to look into the private lives of reporters, several academic experts said.

“The question is not ‘Do they investigate,’ the question should be ‘Do they harass?’ ” said the Rev. Robert W. Thornburg, dean of Marsh Chapel at Boston University and a recognized expert on destructive religious practices. “And Scientology is far and away the most notable in that.

“No one I know goes so far as to hire outsiders to harass or try to get intimidating data on critics,” said Thornburg. “Scientology is the only crowd that does that.”

The Rev. Richard L. Dowhower, a Lutheran minister and an adviser on cult activity at the University of Maryland, College Park, said, “I’ve been in the cult-watching business since the early ’70s and I don’t know of any other group, other than Scientology, that targets journalists.”

And Hal Reynolds, student affairs officer at the University of California, Berkeley, and director of the campus Cult Education Center, also said Scientology investigates journalists.

“I’ve been collecting files on these groups for 10 years, and I have not heard of that for any other group,” Reynolds said.

The March 1-5 Herald series described how the Church of Scientology recruited an MIT student, persuaded him to drop out of school and sign a billion-year contract to serve the church, and asked him to spend student loan money on Scientology courses.

The series also described how two Scientology-linked groups, Narconon and the World Literacy Crusade, have used anti-drug and learn-to-read programs to gain access to public schools without disclosing their Scientology ties.

Earle Cooley, a Church of Scientology lawyer from Boston, recently publicly defended the church’s policy of investigating journalists.

“I don’t know where it says anywhere in the world that it’s inappropriate for the investigators to be investigated,” Cooley said during a WGBH-TV talk show two weeks ago.

In a written statement, Cooley said he played no part in hiring private investigators to look into Mallia’s personal life.

Here is how Scientology is reported to have dealt with other journalists:

Nov. 1997: In England, a Scientology detective obtained a BBC television producer’s private telephone records to conduct a noisy investigation” by spreading false criminal allegations about the producer, the Daily Telegraph newspaper reported.

1990-1991, New York: Scientology used at least 10 lawyers and six private detectives to “threaten, harass and discredit” Time magazine writer Richard Behar, who wrote an article titled “Scientology: the Cult of Greed.”

1988: A St. Petersburg (Fla.) Times reporter who wrote articles about Scientology said his credit report was obtained without his consent, his wife got obscene phone calls, and a private investigator followed him.

1983: Scientology defectors admit they stole documents from The Boston Globe’s law firm, Bingham Dana & Gould, in late 1974 to gain information about a planned Globe article on Scientology.